... you can save almost as much power by leaving the camera in Playback mode with the backlight off at startup ...
Thanks for that tip! Camera stays asleep in play mode even if I shake it. I am running a test now on how long I can take pics after a 45 minute wait time with camera switched to play/backlight off. (flight was delayed due to weather). I let a test run last night with the code reyalp posted forcing it to sleep again when waking (but I couldn't shake it all night). For that test I got 170 minutes with pics every 3 seconds.
What is on the display may also affect the power consumption... It might therefore be worth switching off the backlight, and filling the screen with color(255,255,255) or color(0,0,0) and seeing if this has much effect.
Interesting. I'm tempted to modify waterwingz' battery test script to just test sleeping with display off and different color values, but everything I read (except for the article you quote, which I also found), indicates that it will likely be difficult to detect the difference.. If I change the pixel values every 20 minutes or so in the script I should be able to detect whether there is a different rate of discharge correlating with color change though. tempting...